Gastro - extra

Question 1

How does omeprazole work?

Answer 1

Omeprazole is a proton pump inhibitor (PPI) which inhibits H+/K+-ATPase, which is found in parietal cells

Question 2

What artery is most likely affected in a gastrointestinal bleed?

Answer 2

The gastroduodenal artery

Question 3

What anti-emetic should not be used in a patient who is vomiting due to intestinal obstruction?

Answer 3

Metoclopramide –> a dopamine antagonist but also has an agonist effect on peripheral 5HT3 and antagonist effect on muscarinic receptors to promote gastric emptying.

• In intestinal obstruction, gastric emptying is not possible and this effect is undesirable

Question 4

A man becomes dehydrated due to diarrhoea and vomiting. This is detected by his kidneys and the renin-angiotensin-aldosterone system is activated. This increases the pressure across the glomerulus and maintains glomerular filtration rate.

What is the normal passage of blood through this area?

afferent arteriole –> glomerular capillary bed –> efferent arteriole –> peritubular capillaries and medullary vasa recta

The majority of glucose reabsorption in the nephron occurs within the proximal convoluted tubule

Question 5

Where does the majority of glucose reabsorption occur in the nephron?

Answer 5

The majority of glucose reabsorption in the nephron occurs within the proximal convoluted tubule

Question 6

Where is cholecystokinin (CKK) produced?

Answer 6

I cells, located in the duodenum and jejunum, produce cholecystokinin (CCK) in response to the presence of fats and proteins in the small intestine.

• CCK stimulates gallbladder contraction, releasing bile, and relaxes the sphincter of Oddi, allowing bile and pancreatic enzymes to enter the duodenum for fat digestion